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covered by methods of investigation similar to those pursued by 

 Wohler and Liebig. 



We must not, however, omit to mention other researches carried 

 out during Wohler's stay in Berlin and Cassel, and which are no less 

 important than the work he did with Liebig. His researches extended 

 into every department of chemistry. In 1826 he succeeded in finding 

 a method for obtaining nickel and cobalt from their ores free from 

 arseniCj and thereby laid the foundation of an extensive industry. 

 His appointment as teacher of the new manufacturing school gave 

 him opportunities of helping industries connected with chemistry, and 

 he became more conversant with such industries through a visit he 

 paid to France in 1833, and to England in 1835. 



In inorganic chemistry we owe to him the discovery of three new 

 elements, that of aluminium (in 1827) of beryllium and of yttrium, 

 besides various other beautiful discoveries. 



We have mentioned that in 1823 Wohler had gained a prize for 

 a research in physiological chemistry on excretions from animal 

 organisms. We must also mention his interesting discoveries in 

 chemical physics. While examining the crystallisation of arsenious 

 acid and of oxide of antimony, he noticed the remarkable fact that 

 each of these bodies appears in two distinct crystalline forms. 



But in organic chemistry we have yet to mention a discovery made 

 by Wohler in the year 1828, which, were it his only discovery, would 

 entitle him to a place of honour in the history of that branch of the 

 science, namely, the artificial formation of urea. In. the previous 

 century, as chemists became more and more occupied with animal 

 and vegetable compounds, they had begun to classify chemical sub- 

 stances under the three headings of mineral, vegetable, and animal, 

 but on account of the similarity between the two latter categories 

 Lavoisier placed them in one class, which he called organic in contra- 

 distinction to the mineral or inorganic bodies. 



Rouelle had found when examining urine in 1773 a beautiful 

 crystalline organic substance. This was more minutely examined in 

 1779 by Fourcroy and Yauquelin and named urea. In 1828 Wohler 

 obtained these same long, white, glistening, needle-like crystals with- 

 out the aid of any animal organism by gently heating the ammonia 

 salt of cyanic acid. 



This artificial production of an organic body at once abolished the 

 doctrine of a distinct boundary line between organic and inorganic 

 chemistry, together with the doctrine of vital force. 



Shortly after this discovery Wohler was appointed Professor of 

 Chemistry to the Medical Faculty in the University of Grottingen, 

 and about the same time he became Inspector- General of Pharmacies 

 in the Kingdom of Hanover. 



Wohler now began a long and useful career of teaching. The 



